Sleeved Smiths Thermostats

[Fireman049]

If anyone is looking for a Smiths sleeved thermostat (84c) SNG Barratt now do them for £6.00p.

SNG Barratt Tel: 01746 765432. (www.sngbarratt.com).

Part No: CS 1012/76.

 

Hope this helps?

 

(I've ordered mine for the TR and 'E'-type.)

 

Tom.

 

 

[Lebro]

OOps duplicate post - sorry !

Edited August 22, 2014 by Lebro

[Lebro]

That's a good price - is it a bellows type, or wax ?

 

PM sent by the way

 

Bob.

[peejay4A]

That part number is bellows but no sleeve Tom. They have sleeve types ( they call them rings) but which is correct for the TR?

[Lebro]

sleeve type is correct for 4 pot engines

 

Bob.

[peejay4A]

Yes I have one. I didn't make it clear but I as asking which part number on the Barratt site is correct for the 4 cylinder engine.

[Fireman049]

I've just contacted Barratt's and they inform me that the thermostats are not the sleeved type

so I've cancelled my order. They do have the sleeved type but they are very expensive!

 

Tom.

[peejay4A]

This is a ring (sleeve?) type and cheap. But would it fit?

http://www.sngbarratt.com/ProductDetails.aspx?id=5eda0d80-809b-4e8c-ad55-4a9f97a0a41a

[Andy Moltu]

Don't bother - sleeve down the bipass hose and fit an ordinary stat.

[peejay4A]

Aware of that mod Andy but no.

[Lebro]

It looks right to me - I have one fitted, but was a lot more than £10.

this one is 190° = 88°C so a bit higher than it should be - but probably OK.

I am tempted to get one as a spare.

 

Bob.

[mjdearing]

Picture aint the one your going to get Barretts repro'd the bellows stat 10 yrs ago and charged £55 each for em and now are £70 trade Revington has em at £76 .

[WWT338J]

Please excuse my ignorance but what is special about a sleeved thermostat?

Is this something I shouldn't be without or is this something for the councours boys?

 

David

[Don H.]

Please excuse my ignorance but what is special about a sleeved thermostat?

Is this something I shouldn't be without or is this something for the councours boys?

 

David

 

Not concours -- it has to do with the TR's cooling system design and the way the car warms up. There's a bypass hose near the top hose/thermostat housing that routes coolant back to the radiator. This reduces coolant circulation to the block until the engine is up to temperature. When the thermostat opens, the sleeve blocks the bypass and allows greater coolant flow to the engine. Without the sleeve -- or a restrictor orifice in the bypass hose as andymoltu notes -- the efficiency of the system is reduced.

[Lebro]

Surely it's the other way round.

The thermostat blocks the path to the top of the rad, forcing the coolant from the pump, through the bypass hose to the bottom hose, where it goes through the block, & back to the pump.

When hot enough the thermostat opens the path to the top of the rad, & the sleeve closes the path to the bypass hose allowing all the coolant

to be cooled by the rad. Without the sleeve, some coolant will "short circuit" the system, & just go through the block, & back to the pump.

 

Bob.

[peejay4A]

Picture aint the one your going to get Barretts repro'd the bellows stat 10 yrs ago and charged £55 each for em and now are £70 trade Revington has em at £76 .

I don't understand. Are you saying that the stat I linked to, which is sleeved (with ring in their parlance), is not really sleeved?

Edited August 23, 2014 by peejay4A

[Don H.]

I don't understand. Are you saying that the stat I linked to, which is sleeved (with ring in their parlance), is not really sleeved?

 

The links opened awkwardly for me -- asking for a country first -- but the ones I saw were of two types -- both with bellows, but only one with sleeve.

 

Yes, I believe their terminology "ring" referred to the one with the sleeve.

Edited August 23, 2014 by Don H.

[peejay4A]

Look at part number CS1011/80 which is what my link points to.

Edited August 23, 2014 by peejay4A

[Don H.]

Look at part number CS1011/80 which is what my link points to.

 

There were two thermostats available back in the day, as I recall. A "summer" one around 70°C / 160°F and a "winter" one at maybe around 88°C / 190°F. Don't have my notes at hand so those values are approximate; someone here will remind us of the exact details.

 

Here's an ancient post from the US-based "Triumphs" list at team.net with some further comments on Jaguar thermostats in TRs...

http://www.team.net/html/triumphs/1997-08/msg00201.html

[Ashley James]

I'm not sure that is correct. I don't have a skirted thermostat in my Healey or my Bentley. I had all sorts of problems with the Bentley over years that were eventually traced back to a slow acting genuine R-R thermostat which, as you'd expect, is not like any other and costs £180. A Rolls Royce specialist chum who owns one like mine said that he hadn't used the genuine article for years, instead he paid a fiver for a Peugeot one. It comes with a rubber ring round it that makes it fit the larger diameter R-R hole.

 

Just as the Healey and the TR do, so Bentleys and R-Rs have a bypass hose that is cut off by the thermostat as it opens. Also because the engine weighs nearly double the TR and is more than twice the capacity, it gets frigging hot, especially in jams on hot summer days. Under all conditions, the Peugeot one keeps the engine a few degrees cooler than the £180 job and my son now suggests them as an alternative to customers who may well be driving in Spain or Southern Italy in high summer.

 

On our industrial estate is a Morgan specialist who offers both styles and he too is off the opinion that a modern thermostat without skirt is just as good as the original.

 

The problem is that with a clear block, a perfect water pump and radiator, all these old cars can get too hot in the hottest weather. The cooling system is a bit marginal, but in my experience, changing to a later and better Thermostat doesn't make things worse. It might be better because it reacts more quickly.

[peejay4A]

Ashley, you seem to have debunked the technique of restricting the bypass hose if you are using a plain thermostat. I've no experience other than using the sleeved type on my car so I can't offer an opinion but I'll bet there will be some who will

[Ashley James]

We didn't bother to restrict the bypass hose because there didn't appear to be a need. Fact is that for about a fiver anyone can test my theory for themselves and given the amount of rubbish that appears on the internet, that might be wise.

[Don H.]

Ashley, there sre some folks over here -- highly competent in TR mechanicals -- who run a regular thermostat and can see no difference compared to sleeved. I put a lot of faith in one guy particularly.

 

The efficiciency gains/losses from the bypass system, with sleeved bellows-type t-stat or cheapo wax pellet or restrictor orifice, are inconsequential to the performance of his TR3A, he notes.

 

I suspect you're right, although I haven't run the experiments myself -- keep flow rates good and heat transfer surfaces clean, and use whatever t-stat you like.

Edited August 24, 2014 by Don H.

[Ashley James]

I agree Don. My slight worry with the old type is that they might be old stock or made in small quantities and not very well. Same old story with lots of pattern stuff. At least with a new one it's a mass market product and likely to be okay.

[peejay4A]

I'd be happy to try a standard thermostat in mine but for the possibility of overheating in extreme conditions due to the bypass shunting the radiator. That and the bother of having to do a roadside fix should it go wrong. That said my cooling system is all new, liners replaced etc so maybe I'll carry a standard stat as a spare.